Funds are requested to purchase a Leica Laser Microdissection System to be shared by the laboratories of eight faculty, and will be made available for occasional use by other members of the UT Southwestern faculty. The primary users group includes members of the following departments, Molecular Biology (4), Internal Medicine (2), Cell Biology (1) and Pathology (1) of whom NIH currently funds 6. Space for the microscope will be provide by the department of Internal Medicine and the administration of the grant and management of the instrument will be supervised by a cross departmental committee. [unreadable] [unreadable] Projects proposed by the current users group include the following studies: (1) Identification of genes involved in calcium signaling pathways in skeletal and cardiac muscle (Olson); (2) Identification of genes involved in early heart development (Olson); (3) Identification of genes differentially expressed along the length of the linear heart tube (Olson); (4) Define the genetic regulatory program associated with the developing somite (Garry); (5) Analyze the gene expression pattern from wild type or mutant mouse hearts lacking essential cardiac transcription factors (Srivastava); (6) Compare gene expression in the specialized smooth muscle of the ductus arteriosus to the adjacent aortic smooth muscle (Srivastava); (7) Identification of transcription factors that establish and maintain the developmental program specific for the exocrine pancreas (MacDonald); (8) Identification of regulatory genes that control salivary gland development (MacDonald); (9) Identification of specific regulatory genes during neuronal differentiation controlled by bHLH factors in the developing spinal cord (Johnson). [unreadable] [unreadable]